US 6,203,956 B1Granted

Electrophotographic toner and image-forming method

AssigneeFuji Xerox Co., Ltd.

InventorsChisato Urano, Katsumi Daimon, Masato Mikami, Norihito Fukushima

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Abstract

An electrophotographic toner containing a binder resin and a colorant, wherein at the angular frequency of 1 rad/sec and 30° C., a storage elastic modulus (G′30) is at least 1×105 Pa and a loss elastic modulus (G″30) is at least 1×105 Pa; a melting point is in the temperature region of 45 and 110° C.; when a common logarithm of G′ is plotted against the temperature and G′ at melting point +20° C. is represented by G′ (Tm+20) and G′ at melting point +50° C. is represented by G′ (Tm+50) the condition of the following formula (1) is satisfied |logG′(Tm+20)−logG′(Tm+50)|≦1.5 (1); and when a common logarithm of G″ is plotted against the temperature and G″ at melting point +20° C. is represented by G″ (Tm+20) and G″ at melting point +50° C. is represented by G″ (Tm+50), the condition of the following formula (2) is satisfied |logG″(Tm+20)−logG″(Tm+50)|≦1.5 (2). The electrophotographic toner is good in a low-temperature fixing property and an offset resistance, has a wide fixing latitude and is capable of oilless fixing.

Claims14

Dependent claims

A toner comprising a crosslinked binder resin and a colorant, the toner satisfies the following properties (a) to (e):

(a) a melting point is in the temperature range of about 45 to 110° C.;
(b) at an angular frequency of 1 rad/sec and 30° C., a storage elastic modulus (G′30) is at least 1×105 Pa and a loss elastic modulus (G″30) is at least 1×105 Pa;
(c) the values of the storage elastic modulus (G′) and the loss elastic modulus (G″) are changed 102 or more within a temperature range of about 10° C. when the temperature is varied;
(d) when the storage elastic modulus at a temperature of melting point plus 20° C. is represented by G′ (Tm+20) and the storage elastic modulus at a temperature of melting point plus 50° C. is represented by G′ (Tm+50), the condition of the following formula (1) is satisfied
|logG′(Tm+20)−logG′(Tm+50)|≦1.5 (1);
and
(e) when the loss elastic modulus at a temperature of melting point plus 20° C. is represented by G″ (Tm+20) and the loss elastic modulus at a temperature of melting point plus 50° C. is represented by G″ (Tm+50), the condition of the following formula (2) is satisfied
|logG″(Tm+20)−logG″(Tm+50)|≦1.5 (2).

5 more elements

Dependencies are inferred from the claim text.